Measles Epidemics Research Articles

A historical syndemic? The impact of synergistic epidemics of measles and scarlet fever on life expectancy in Victoria, Australia (1860s-1870s).

To explore whether synergistic epidemics of measles and scarlet fever in 1860s-1870s Victoria, Australia could be characterized as syndemics, we apply the methods of Sawchuk, Tripp, and Samakaroon (Social Science & Medicine 2022, 295, 112956) to quantify the impact of each of the two major co-occurring epidemic events (1867, 1875) in terms of life expectancy (LE) changes. Sawchuk et al. posit the presence of a harvesting effect, indicated by a statistically significant increase in LE in the immediate post-epidemic "fallow period", as a criterion for identification of a historical syndemic. We test an alternate hypothesis that the same methods can identify a short-term scarring effect. Using annual age- and cause-specific death statistics and census population data, we constructed abridged period life tables for baseline period, potential syndemic year, and "fallow" year for each of the two periods (1860s and 1870s). We compared LE at birth using Z-tests. We decomposed age-cause-specific mortality according to Arriaga's method to identify age-and cause-specific contributions to LE change. LE was significantly lower than baseline (1864-1865) in 1867 but not in the "fallow" year (1869). LE in 1875 and the 1878 "fallow" year were both significantly below baseline (1871-1873). Age-cause-specific decomposition showed similar patterns for 1867 and 1875 for measles and scarlet fever combined effects. Evidence of a scarring effect following the 1875 measles/scarlet fever combined peak supports the interpretation of this event as a syndemic. We suggest the short-term scarring effect can be a useful additional criterion for identifying historical syndemics.

High rates of hepatic involvement associated with new epidemic measles strains in Romania.

Similar to other European countries, a measles epidemic dominated by D8 genotype strains is ongoing since 2022 in our country. Recent reports of liver involvement associated with new measles virus (MeV) strains are scarce. The aim of the study was to compare the clinical characteristics between hospitalized patients with measles from the current epidemic and those from the previous outbreak and to analyze the risk factors associated with hepatic involvement. Data were collected retrospectively for all consecutive adult ( ≥18 years old) patients admitted between October 2022-April 2024 and January 2018-December 2019. A number of 228 patients from the current and 130 from the previous MeV epidemic were included. The main statistically significant differences were those regarding hepatic involvement (77.2% vs. 45.4%, p < 0.001) and significant hepatocellular injury (23.6% vs. 10.7%, p = 0.003). Compared to cases without liver involvement (123), patients with hepatocytolysis (235) had a higher prevalence of keratoconjunctivitis (42.5% vs. 28.4%, p = 0.01), thrombocytopenia (47.6% vs. 34.9%, p = 0.02), severe lymphopenia (51% vs. 35.7%, p = 0.007) and high fibrinogen levels (58.7% vs. 47.1%, p = 0.04). MeV strains from the 2022-2024 epidemic were the strongest predictors of hepatic involvement in the multivariable analysis (odds ratio = 4.3, 95% confidence interval: 2.5-7.4, p < 0.001). The mortality rate of patients with hepatocellular injury was 1.2%. The current measles epidemic is dominated by high rates of hepatic involvement compared to the previous outbreak. Although not associated with a significant mortality, the potential change in MeV hepatotropism could have important clinical implications and warrants further monitoring.

Measles Epidemic in South India in 2024

Measles Epidemic in South India in 2024

Sensitivity stability and feasibility analysis of epidemic measles using mathematical SEIR model

Sensitivity stability and feasibility analysis of epidemic measles using mathematical SEIR model

Epidemic in the time of the COVID-19 pandemic: News media framing of the MMR vaccination controversy in Serbia

Rising vaccine hesitancy is often related to negative vaccination media coverage. It is generally accepted that the media played a great role in spreading the MMR (measles, mumps, and rubella) childhood vaccination scare first in the UK and then worldwide. During the COVID-19 pandemic, the MMR vaccination rate dropped further in some countries. This paper examines the Serbian news media framing of the MMR vaccination controversy in the period 2019–2023 (periods of declining MMR vaccination rate, rising COVID-19 vaccine hesitancy and the 2023 measles outbreaks). Furthermore, the paper questions whether the COVID-19 pandemic influenced the MMR vaccine narrative in the newspapers. For this reason, quality content analysis of the press in combination with framing approaches (diagnostic–prognostic–motivational framing tasks and responsibility framing) were used. In total, 122 articles dealing with the MMR vaccine and measles epidemics were analysed. According to the press, the most significant cause of the declining MMR rate is anti-vaccination campaigns and conspiracy theories by the “anti-vax lobby” (diagnostic frames). The pandemic was the other significant cause for the intake drop. Achieving herd immunity through vaccine uptake is offered as the best solution (prognostic frames). Finally, MMR vaccination campaigns and penalties for non-compliant parents and vaccine refusers are proposed as calls to action (motivational frames). During this period, the press did not publish any “sensational anti-vax stories”. Considering the low MMR vaccine numbers in Serbia in this period, positive media messages did not have a significant influence on improving the vaccination rate. Thus, I suggest that Serbian parents distrust vaccination information presented by the dominant news, including the advice of health experts.

Epidemiological study of the occurrence of measles in children aged 0-15 years in the Banalia Health Zone (DR Congo) during 2022

Introduction: In 2021, the Banalia Health Zone experienced two measles epidemics with a vaccine completeness rate of 69% according to data provided by the Tshopo Provincial Health Division. The aim of the study was to list the epidemiological characteristics of measles cases in the Banalia Health Zone, to determine the incidence of measles in children aged 0-15 years, and to analyze the vaccination status of children with measles. Methodology: This was a retrospective descriptive study, based on the acquisition of data from the medical records of the targeted children or from data registers at the time of submission. A total of 3,968 children with measles were selected from the various health centers and areas of the Banalia Health Zone. Results: We observed that 64.6% of the subjects in the study were aged between 0 and 5 years; 40.77% of measles cases were recorded in September 2022. The measles vaccination rate was 39.19% and the case fatality rate was 2.8%. The Panga 2 axis had the highest number of measles cases, with a prevalence rate of 29.03%. Conclusion: Measles is a major cause of morbidity and mortality in the Banalia Health Zone. The age group most affected is 0-5 years. Vaccination and surveillance systems need to be strengthened to reduce the growing risk posed by measles.

Suboptimal MMR Vaccination Coverages-A Constant Challenge for Measles Elimination in Romania.

Measles is targeted for elimination since 2001, with a significant reduction in cases recorded worldwide, but outbreaks occur periodically due to immunization gaps. This study analyzes the evolution of vaccination coverage rates (VCRs) in Romania, a EU country with large measles epidemics during the last two decades, including an ongoing outbreak in 2023. Vaccination against measles has been part of the National Immunization Program since 1979, initially as a single dose, and from 1994 onwards it has had two doses. The initially high national VCRs of >97% gradually declined from 2010 onward and remained constantly under 90%, with further decreases during the COVID-19 pandemic. The lowest VCRs for both vaccine doses in the last decade were recorded in 2022 and were 83.4% for the first dose and 71.4% for the second dose, with significant differences among Romania's 42 counties. Several factors contributed to this decline, including failure to attend the general practitioners' offices, increased number of children lost to follow-up due to population movements, missed vaccination opportunities due to temporary medical contraindications, a surge in vaccine hesitancy/refusal, a decreasing number of general practitioners and discontinuities in vaccine supply. The persisting suboptimal VCRs in Romania threaten the progress toward measles elimination.

Measles Outbreaks in the Republic of Congo: Epidemiology of Laboratory-Confirmed Cases Between 2019 and 2022.

In Africa, measles epidemics are frequently reported, despite numerous preventive measures, such as vaccination, which targets children under 5 years of age. Unfortunately, the Republic of the Congo is not an exception to this major health concern. Indeed, many cases are reported annually. Here, we provide an overview of the epidemiological characteristics of laboratory-confirmed measles cases from January 2019 to October 2022 as well as the risk factors associated with the occurrence of measles outbreak. Samples from suspected measles cases were collected across the country and sent to the National Laboratory of Public Health for confirmation. Specific IgM was tested using the enzyme-linked immunosorbent assay (ELISA). Data were analyzed using descriptive and analytic statistics (p < 0.05 was statistically significant). A total of 1330 samples were collected and analyzed. Over those 4 years, 537 samples were confirmed to be positive (40.3%) but with important disparities between years. A relatively low frequency of cases was reported in 2020. Overall, a progressive and significant evolution of positive cases was observed between 2019 and 2022, increasing from 16.8% in 2019 to 65.9% in 2022 (p < 0.0001). We report a low vaccination rate among children (44.8%) and a significantly high positivity rate in this group (46.6%) (p < 0.0008). No difference was reported according to the completeness of the vaccination scheme (p=0.094). Females were slightly more exposed to this infection than males (p=0.04; adjusted odds ratio [aOR]: 1.25 [1.01-1.6]), with an increased risk of exposure in rural areas (p=0.0001; aOR: 0.41 [0.32-0.53]). The department of Pointe-Noire had the highest positivity rate, while three other departments were considered high-risk areas: Likouala (p = 0.0001; aOR: 3.18 [1.80-5.61]), Pool (p=0.0001; aOR: 2.90 [1.70-4.95]), and Brazzaville (p=0.0005; aOR: 0.52 [0.36-0.75]). This study calls for strengthening the epidemiological surveillance system and vaccination strategy in the country. It remains important to research factors that induce a high positive rate among vaccinated children by biological verification of the immunization.

Vaccination and Measles Epidemic in the Republic of Congo

Vaccination and Measles Epidemic in the Republic of Congo

Program eliminacije morbila u Evropi

The use of a safe and effective measles vaccine in national immunization programs has resulted in a reduction in the number of deaths from the disease, although measles remains one of the leading causes of death in children under 5 years of age in underdeveloped and developing countries. After the successful eradication of smallpox, as well as the results achieved in the eradication of poliomyelitis at the global level, the process of measles elimination was initiated using the previously known strategies. In both American regions of the World Health Organization (WHO), the elimination of measles has been successfully verified, while in the WHO European Region, up to 2020, elimination has been verified in 29 out of 53 countries. The main challenges in the process of measles elimination are reaching and maintaining high immunization coverage, reaching and maintaining the values of surveillance indicators, implementing additional immunization of unvaccinated and incompletely vaccinated persons, solving serious problems such as the occurrence of measles epidemics in vulnerable groups, endemic maintenance of the disease, re-establishment virus transmission, determination of chains of transmission, genotyping of agents, impact of measures to control the COVID-19 pandemic. Bearing in mind the mentioned problems, the WHO has decided to postpone the elimination of measles in the WHO European Region to the year 2030.

Seroprevalence of Measles in Pairs of Mothers and Newborns in Southern Greece.

Maternal immunoglobulin G (IgG) antibodies that are passively transferred to newborns through the placenta confer protection if they are exposed to measles virus. A measles outbreak occurred in several European countries including Greece, between 2016 and 2018. A prospective study was conducted in the General Hospital of Lakonia, regarding the measles seropositivity status of mother and newborn pairs. IgG antibody titer for measles was measured in serum samples acquired from pairs of mothers and newborns. The samples were analyzed through quantitative enzyme-linked immunosorbent assay, and antimeasles IgG >200 IU/mL was considered to be protective. Demographic data for mothers and neonates and data regarding immunization status of mothers were analyzed. Study population included 206 mothers and their newborns. In total, 12.6% of mothers (n = 26) and 10.7% of newborns (n = 22) did not have protective serology. A statistically significant positive linear association between maternal and neonatal antibodies was found (rho = 0.924) (p = 0.001). Neonates whose mothers were seropositive had higher antibodies [geometric mean concentration (GMC): 804.8 (728.3-889.2)] than neonates whose mothers were seronegative/borderline [GMC: 97.7 (64.2-148.8)] (p = 0.001). In the study area, a significant rate of mothers and newborns was found to have nonprotective measles serology that exceeds the limit required for herd immunity. Vaccination coverage in women of reproductive age should be increased to reduce potential for future measles epidemics.

Retrospective Analysis of the Epidemiological Profile of Measles in 2022 in Mali

Measles is a highly contagious viral disease caused by the morbillivirus of which humans are the only reservoir. Our descriptive study aims at analyzing retrospective measles surveillance data from 2022. Of the 2037 suspected measles case samples received at the laboratory, 784 (38%) were confirmed. The age group of 1-4 years is the most affected with an attack rate of 25.43 per 100,000 inhabitants. Children under 5 represent 47.71% of cases. The median age is 4 years and the average age 6.14 years (0 months-54 years). The male sex represents 51% of cases with a sex ratio of 1.06 and an attack rate of 9.72 per 100,000 inhabitants. Most confirmed measles cases (71.77%) were recorded during the dry season. The districts of Koutiala (140 cases: 17.85%), Sikasso (127 cases: 16.19%), Ségou (109 cases: 13.09%) and Bougouni (98 cases: 12.5%) record the most case. The average time for feedback from the laboratory was 3.95 days. Moreover, among the 1253 sample cases negative for measles, 8.22% were positive for rubella. The median age of patients was 6 years. Children under five are the most affected. Most of these cases are in unvaccinated people. The establishment of an enhanced vaccination program at country level considering the most affected groups could reduce the resurgence of measles epidemics. Keywords: Epidemic, Measles, Mali, Notifiable disease (MADO), Spatiotemporal.

Strong biological correlations as a cause of autonomous oscillations in epidemics.

We consider the impact of strong biological correlations on the epidemic process. The biological correlations mean the influence of the environment on the individual state of immunity of the infected person. Accounting for the correlations turns the traditional SIRS model into the 3D Lotka-Volterra model, the parameters of which are uniquely determined by the parameters of the original SIRS model. The measure of the biological correlations in the epidemic is the correlation strength parameter [Formula: see text], where [Formula: see text] and [Formula: see text] are the duration of the infectious period of the disease and the duration of immunity, respectively, both measured in years. If the epidemic is highly correlated ([Formula: see text]), then after the first epidemic outbreak, subsequent oscillations occur, the period [Formula: see text] of which is less than one year. The example is the COVID-19 pandemic. If the epidemic is weakly correlated ([Formula: see text]), the period [Formula: see text] of the oscillations is more than one year. Then in the presence of regular annual outbreaks the oscillations do not have time to manifest themselves. The examples are the ordinary flu annual epidemics. In the absence of the annual epidemic factor, the oscillations can exist and persist regardless of the [Formula: see text] value. The examples are the measles epidemics. The 3D Lotka-Volterra model makes it possible to predict the period [Formula: see text] of the future oscillations based on two known clinical parameters-[Formula: see text] and [Formula: see text]. This period turns out to be equal to 2π multiplied by the geometric mean of the duration of the infectious period of the disease [Formula: see text] and the duration of immunity [Formula: see text]. The adequacy of the 3D Lotka-Volterra model is supported by examples of the 2017-2019 annual flu epidemics and the 2020-2022 COVID-19 epidemic in Israel, as well as the succession of measles epidemics in the UK between 1940 and 1970.

Two-dose measles vaccine effectiveness remains high over time: A French observational study, 2017–2019

BackgroundFrom 2008 to 2019, France has experienced a resurgence of measles epidemics. Surveillance data have shown that the proportion of cases vaccinated with two doses of measles-containing vaccine (MCV) increased with age, raising concerns about the duration of vaccine protection. Our objectives were to investigate age-stratified vaccine effectiveness (VE) for the second dose of MCV (MCV2) and to quantify protection levels over time. MethodsWe analyzed data on measles cases aged 2–31 years, reported via mandatory notification to the French measles surveillance system from October 2017 to September 2019. We estimated an age-stratified VE for MCV2 using the screening method, which compares the vaccination status of cases with that of the general population. We improved this method by accounting for natural immunity, exploring four scenarios with four possible levels of natural immunity in the population. In addition, we quantified the decay rate of protection over time, by fitting an exponential decay model among individuals vaccinated in early life. ResultsIn the baseline analysis (absence of natural immunity), VE estimates were high in all age groups and decreased with age, from 99.6 % (95 % confidence interval: 99.3–99.8) in 2–5 years old to 91.4 % (85.1–95.0) in 26–31 years old. Accounting for natural immunity increased VE in the older age group to 93.2–99.2 % depending on the scenario. We estimated that VE was slowly decreasing over time, with an exponential decay rate of 0.0022/year (0.0017–0.0028), leading to VE of 96.7 % (96.0–97.4) 16 years after MCV2 vaccination. This decline was most compatible with scenario 2, a scenario of 4.4 % naturally immunized, non-vaccinated individuals in the 26–31 years old. ConclusionOur study confirms the continued high effectiveness of two doses of MCV with only slight degradation, decades after immunization. These findings support the importance of achieving a very high vaccination coverage with 2 doses of MCV.

Impact of Lévy Noise with Infinite Activity on the Dynamics of Measles Epidemics

This research article investigates the application of Lévy noise to understand the dynamic aspects of measles epidemic modeling and seeks to explain the impact of vaccines on the spread of the disease. After model formulation, the study utilises uniqueness and existence techniques to derive a positive solution to the underlying stochastic model. The Lyapunov function is used to investigate the stability results associated with the proposed stochastic model. The model’s dynamic characteristics are analyzed in the vicinity of the infection-free and endemic states of the associated ODEs model. The stochastic threshold Rs that ensures disease’s extinction whenever Rs&lt;1 is calculated. We utilized data from Pakistan in 2019 to estimate the parameters of the model and conducted simulations to forecast the future behavior of the disease. The results were compared to actual data using standard curve fitting tools.

Modelling and Analysis of a Measles Epidemic Model with the Constant Proportional Caputo Operator

Despite the existence of a secure and reliable immunization, measles, also known as rubeola, continues to be a leading cause of fatalities globally, especially in underdeveloped nations. For investigation and observation of the dynamical transmission of the disease with the influence of vaccination, we proposed a novel fractional order measles model with a constant proportional (CP) Caputo operator. We analysed the proposed model’s positivity, boundedness, well-posedness, and biological viability. Reproductive and strength numbers were also verified to examine how the illness dynamically behaves in society. For local and global stability analysis, we introduced the Lyapunov function with first and second derivatives. In order to evaluate the fractional integral operator, we used different techniques to invert the PC and CPC operators. We also used our suggested model’s fractional differential equations to derive the eigenfunctions of the CPC operator. There is a detailed discussion of additional analysis on the CPC and Hilfer generalised proportional operators. Employing the Laplace with the Adomian decomposition technique, we simulated a system of fractional differential equations numerically. Finally, numerical results and simulations were derived with the proposed measles model. The intricate and vital study of systems with symmetry is one of the many applications of contemporary fractional mathematical control. A strong tool that makes it possible to create numerical answers to a given fractional differential equation methodically is symmetry analysis. It is discovered that the proposed fractional order model provides a more realistic way of understanding the dynamics of a measles epidemic.

Determinants of measles persistence in Beijing, China: A modelling study.

In Beijing, the capital of China, routine measles mass vaccination has been in place for decades with high coverage; and since the 2000s, catch-up vaccination programmes have been implemented for migrant workers coming to the city. However, measles epidemics in Beijing persisted. Here, we explored the contributing factors of persistent measles transmission in Beijing using an epidemic model in conjunction with a particle filter. Model inputs included data on birth, death, migration, and vaccination. We formulated a series of hypotheses covering the impact of migrant influx, early waning of maternal immunity, and increased mixing among infants; we compared the plausibility of the hypotheses based on model fit to age-grouped, weekly measles incidence data from January 2005 to December 2014, and out-of-fit prediction during 2015-2019. Our best models showed close agreement with the data, and the out-of-fit prediction generally captured the trend of measles incidence from 2015 to 2019. We found that large influx of migrants with considerably higher susceptibility likely contributed to the persistent measles transmission in Beijing. Our findings suggest that stronger catch-up vaccination programmes for migrants may help eliminate measles transmission in Beijing.

Comparing and linking machine learning and semi-mechanistic models for the predictability of endemic measles dynamics.

Measles is one the best-documented and most-mechanistically-studied non-linear infectious disease dynamical systems. However, systematic investigation into the comparative performance of traditional mechanistic models and machine learning approaches in forecasting the transmission dynamics of this pathogen are still rare. Here, we compare one of the most widely used semi-mechanistic models for measles (TSIR) with a commonly used machine learning approach (LASSO), comparing performance and limits in predicting short to long term outbreak trajectories and seasonality for both regular and less regular measles outbreaks in England and Wales (E&W) and the United States. First, our results indicate that the proposed LASSO model can efficiently use data from multiple major cities and achieve similar short-to-medium term forecasting performance to semi-mechanistic models for E&W epidemics. Second, interestingly, the LASSO model also captures annual to biennial bifurcation of measles epidemics in E&W caused by susceptible response to the late 1940s baby boom. LASSO may also outperform TSIR for predicting less-regular dynamics such as those observed in major cities in US between 1932–45. Although both approaches capture short-term forecasts, accuracy suffers for both methods as we attempt longer-term predictions in highly irregular, post-vaccination outbreaks in E&W. Finally, we illustrate that the LASSO model can both qualitatively and quantitatively reconstruct mechanistic assumptions, notably susceptible dynamics, in the TSIR model. Our results characterize the limits of predictability of infectious disease dynamics for strongly immunizing pathogens with both mechanistic and machine learning models, and identify connections between these two approaches.

Biological Profile and Clinical Features as Determinants for Prolonged Hospitalization in Adult Patients with Measles: A Monocentric Study in Western Romania.

Measles is a highly infectious and sometimes deadly illness that is preventable with vaccination. The present research aims to analyze the most recent measles epidemic from Romania that occurred in a population with a falling desire to receive immunizations, by detailing the clinical picture and biological profile of hospitalized patients. A secondary goal of the present research is to identify characteristics that increase the likelihood of a longer hospitalization and the development of measles-related pneumonia. A retrospective cohort study was conducted to follow the course and effects of measles virus infection in adult hospitalized patients who were divided into two groups based on whether they had been in the hospital for more than 6 days or fewer than 6 days. A total of 114 adult patients with measles were eligible to participate in the trial if they had a positive measles-specific IgM antibody test resulting from the study. The average age in the short hospital stay group was 28.1 years, while the average age in the long hospital stay group was 31.9 years. There was a statistically significant difference in the number of Roma persons in the research groups, with 17.4 percent of them having a lengthy hospital stay compared to 5.9 percent in the group with a short hospital stay, according to the findings. It was observed that many patients had a long hospitalization associated with chronic lung disease (OR = 1.07), liver damage (OR = 1.66), Roma ethnicity (OR = 1.79), a long duration elapsed from the last MMR dose (OR = 2.02), elevated c-reactive protein (OR = 2.17), the presence of bilateral pulmonary condensations on X-ray (OR = 3.13), and elevated procalcitonin (OR = 3.49). The same significant independent risk factors were also associated with the development of pneumonia. It is of imperative need to address these risk factors in a patient with measles, moreover in association with an unknown status of vaccination. Vaccination awareness against measles must be pushed in Romania to determine a higher than 95% coverage. Significant efforts are still needed to ensure improved protection against measles epidemics within a specific region or population and, more importantly, in patients with significant risk factors for complications, as described in this study.

Patterns of population decline following European contact and colonization: The cases of Tahiti and the Marquesas

Recent archaeological data assess that Tahiti and the Marquesas Islands were densely populated at contact with the Europeans and then experienced a tremendous decline. This phenomenon is most often attributed to epidemics, while a steady negative increase is rarely mentioned. This paper shows that the population of Tahiti was most probably around 110,000 – or even reached 180,000 – at contact, based on a retrodiction from the 1881 census using data on epidemic mortality and annual decline rates observed in the second half of the nineteenth century in Tahiti, the Marquesas, and other Eastern Polynesian islands in similar situations, according to missionary, administrative, and medical reports. Our ‘model’, or reconstitution, provides estimates on the impact of both types of mortality. Due to no exposure to childhood and other diseases common on the continents, the Polynesians had low immunity, as shown by age-specific death rates until the 1918 flu and the 1951 measles epidemics. Following the European contact, sexually transmitted diseases (STDs), tuberculosis (TB), and other introduced infectious diseases resulted in a steady population decline due to reduced birth rates and very high death rates. Health services were available for the Europeans soon after the takeover, however the natives got access to health services much later with their sporadic and fragmental provision. The constant negative increase extended far beyond the colonial period, including after effective drugs were discovered in the 1880s, becoming the main contributor to the overall demographic decline in the Marquesas, where health services were missing most of the time before 1924, mostly in the South-Eastern group.